Direction and Range of Condylar Positional Changes in the First-Year Post-surgical Orthodontics Interventions in Adult Patients with Skeletal Class III Deformity: A Systematic Review and Meta-analysis.

Objectives: Assess the available scientific literature regarding the direction and extent of condylar positional changes during the first year of post-surgical orthodontics interventions in class III patients. Materials and Methods: PubMed, Cochrane Library, Embase, and Google Scholar databases were searched up to March 2022 for studies involving the measurement of condylar positional changes after surgical treatment of Class III dentofacial deformity in adults with BSSO without or without Le Fort I osteotomies. The methodological index for non-randomized studies (MINORS) was utilized to assess the risk of bias and quality of non-randomized studies. Reporting of this review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Primary outcome was condyle positional changes between the following time points: T0: before treatment, T1: immediately post treatment, T2: 4, 6, or 9 months post treatment, T3: one year post treatment. Results: Nineteen studies were included in the systematic review. Eleven studies were deemed low quality, and the rest were of medium quality. The meta-analysis included 12 studies and showed statistically significant downward, outward positional changes at T1(Immediately after surgery). Inward Yaw rotation was significant at T1(1-4 month post-surgery) and T2(4-9 months post-surgery). Conclusion: Surgically induced condylar changes tend to go back to normal within the first year after surgery, except for condylar yaw rotations.

Management of Class III Malocclusion with Microimplant-Assisted Rapid Palatal Expansion (MARPE) and Mandible Backward Rotation (MBR): A Case Report.

Class III malocclusion prevalence varies significantly among racial groups, with the highest prevalence observed in southeast Asian populations at 15.80%. These malocclusions often involve maxillary retrognathism, mandibular prognathism, or both, accompanied by maxillary constriction and crossbites. Comprehensive treatment should address anteroposterior, transverse, and vertical imbalances. Microimplant-assisted rapid palatal expansion (MARPE) has shown high success rates for transverse maxillary expansion in late adolescents and adults, presenting a viable alternative to surgically-assisted rapid palatal expansion (SARPE). This case report aims to demonstrate the successful treatment of a young adult female with borderline Class III malocclusion using MARPE and mandibular backward rotation (MBR) techniques. A 21-year-old female presented with a Class III skeletal pattern, anterior/posterior crossbites, and mild dental crowding. Despite her concerns about a concave facial profile, the patient declined orthognathic surgery due to a negative experience reported by a friend. The treatment plan included MARPE to correct maxillary transverse deficiency and MBR to alleviate Class III malocclusion severity. Lower arch distalization was performed using temporary anchorage devices (TADs) on the buccal shelves, and Class II elastics were used to maintain MBR and prevent retroclination of the lower labial segment during anterior retraction. Significant transverse correction was achieved, and the severity of Class III malocclusion was reduced. The lower dentition was effectively retracted, and the application of Class II elastics helped maintain MBR. The patient's final facial profile was harmonious, with well-aligned dentition and a stable occlusal relationship. The treatment results were well-maintained after one year. The MARPE with MBR approach presents a promising alternative for treating borderline Class III cases, particularly for patients reluctant to undergo orthognathic surgery. This case report highlights the effectiveness of combining MARPE and MBR techniques in achieving stable and satisfactory outcomes in the treatment of Class III malocclusion.

Simultaneous labial and lingual augmented corticotomy assisted presurgical orthodontics in class III patients: the morphological aspects of the mandibular anterior ridge with cone-beam computed tomography.

OBJECTIVES: This study aims to investigate the changes in alveolar bone following the simultaneous performance of labial and lingual augmented corticotomy (LLAC) in patients with insufficient alveolar bone thickness on both the labial and lingual sides of the mandibular anterior teeth during presurgical orthodontic treatment. MATERIALS AND METHODS: Thirth-five surgical patients with skeletal Class III malocclusion were included: 19 (LLAC group) accepted LLAC surgery during presurgical orthodontic treatment, and 16 (non-surgery group, NS) accepted traditional presurgical orthodontic treatment. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T0) and at the completion of presurgical orthodontic treatment (T1). The amount of vertical alveolar bone and contour area of the alveolar bone in the labial and lingual sides of mandibular incisors were measured. RESULTS: After presurgical orthodontic treatment, the contour area of the alveolar bone at each level on the lingual side and alveolar bone level on both sides decreased significantly in the NS group (P < 0.001). However, the labial and lingual bone contour area at each level and bone level increased significantly in the LLAC group (P < 0.001). The bone formation rate in the lingual apical region was the highest, significantly different from other sites (P < 0.001). CONCLUSIONS: During presurgical orthodontic treatment, LLAC can significantly increase the contour area of the labio-lingual alveolar bone in the mandibular anterior teeth to facilitate safe and effective orthodontic decompensation in skeletal Class III patients. CLINICAL RELEVANCE: This surgery has positive clinical significance in patients lacking bone thickness (< 0.5 mm) in the labial and lingual sides of the lower incisors.

Correlation between oral cavity volume and upper airway changes in skeletal Class III patients undergoing bimaxillary orthognathic surgery: a pilot cone-beam computed tomography study.

OBJECTIVES: To evaluate changes of the upper airway and oral cavity volumes in patients with skeletal Class III malocclusion undergoing bimaxillary orthognathic surgery, and to analyze the correlation between postoperative upper airway decrease and the amount of jaw movement and oral cavity volume reduction. MATERIALS AND METHODS: Thirty patients (16 males and 14 females) undergoing bimaxillary surgery were included. Three-dimensional reconstruction of the upper airway and oral cavity were performed using preoperative (T0) and postoperative (T1) (6 months) cone-beam computed tomography scans. RESULTS: The volume, sagittal area and minimum cross-sectional area of the upper airway were diminished (P < .001). The decrease in volume and minimum cross-sectional area in the oropharyngeal region of the upper airway were weakly correlated with B-point posterior movement (P < .05). Total oral cavity volume was decreased, with maxillary oral volume increasing and mandibular oral volume decreasing (P < .001). Upper airway decrease was highly correlated with total oral volume reduction and mandibular oral volume reduction, with the most significant correlation being with total oral volume reduction (P < .001). CONCLUSIONS: Class III bimaxillary surgery reduced the volume, sagittal area, and minimum cross-sectional area of the upper airway as well as oral cavity volume. Upper airway changes were weakly correlated with anterior-posterior mandibular movement but significantly correlated with oral cavity volume changes. Thus, oral cavity volume reduction is a crucial factor of upper airway decrease in patients with skeletal Class III malocclusion undergoing bimaxillary orthognathic surgery.

Evaluation of the Effects of Orthopedic Treatment on the Dentofacial Structure and Upper Airway of Subjects with Skeletal Class III Malocclusion.

Objective: The present study aimed to evaluate the effect of rapid maxillary expansion (RME) and face mask treatment on the upper airway in patients with maxillary retrusion in two dimensions using digital cephalograms and volumetric evaluation using acoustic rhinometric measurements. Methods: A total of 22 individuals with a concave profile and skeletal and dental Class III malocclusion during growth and development with a mean age of 9.9±1.38 years were included in the study. A bonded RME appliance and a petit face mask were adapted for the patients. Before treatment (T0) and after maxillary protraction (T1), lateral cephalometric films and acoustic rhinometric recordings were obtained. The dependent sample t-test was used for statistical evaluation. Results: Cephalometric analysis revealed forward movement of the maxilla and backward downward rotation of the mandible. A significant increase was observed in the nasopharyngeal and oropharyngeal regions of the upper airway. Three-dimensional evaluation of the upper airway by acoustic rhinometry revealed only an increase in the volumes of the left nasal cavity after decongestant administration. A statistically significant increase in acoustic rhinometric measurements in nasal valves. When the correlation of the cephalometric findings of the nasopharyngeal region with the acoustic rhinometry findings was examined, no statistically significant relationship was found. Conclusion: As a result of this study, we observed an increase in the cephalometric measurements of the nasopharyngeal and oropharyngeal areas. A significant increase was observed in the minimal cross-sectional area measured by acoustic rhinometry.

Nonsurgical class III correction in adolescence using modified fixed reverse twin-block therapy and fixed appliances - a case series.

Skeletal class III malocclusion is a therapeutic challenge in orthodontic practice. Reverse functional appliances such as reverse twin block (RTB) are used to correct class III skeletal and occlusal disharmonies associated with functional anterior shift in growing patients. However, treatment options become limited with increasing age, especially when patients desire nonsurgical and nonextraction camouflage treatment. This report illustrates the successful nonsurgical treatment of class III malocclusion during adolescence and adulthood, exacerbated by a functional anterior shift that resulted in overclosure of the mandible. A modified fixed RTB was utilized to posture the mandible backwards, thereby inducing active clockwise rotation of the mandible. After treatment, patients demonstrated significantly improved maxillomandibular relationships, well-maintained stable occlusion, and facial esthetics. Satisfactory occlusal, esthetic, and functional outcomes achieved in the present cases underline the fact that dentoalveolar changes induced by fixed RTB can be utilized even past a patient's peak pubertal growth period to obtain changes that aid in correcting a class III malocclusion. A synergistic combination of modified fixed RTB therapy accompanied by comprehensive fixed mechanotherapy is a viable treatment alternative for the correction of aptly selected mild to moderate skeletal class III malocclusions associated with functional anterior shift, anterior crossbites, and mandibular overclosure.

Association between mandibular prognathism and Matrilin-1, bone morphogenic protein, Tyr67Asn, homeobox protein hox-A2, Rho-GTPase activating protein, and Myosin 1H genes in the Indian population.

INTRODUCTION: Mandibular prognathism (MP) patients present with aesthetic concerns and functional issues, including difficulties in mastication and pronunciation. Studies revealed that mandibular prognathism had definitive Mendelian inheritance patterns. This study aimed to ascertain distinct genetic markers associated with mandibular prognathism in individuals of Indian descent, focusing on exploring the prevalent genetic variations associated with certain genes. This study sought to identify the association of the following gene markers with mandibular prognathism: 1) Matrilin-1 (MATN1) (rs1065755), 2) Bone morphogenic protein 3 (BMP-3) (Tyr67Asn), 3) Homeobox protein hox-A2 (HOXA2) (Val327Ile), 4) Rho-GTPase activating protein (ARHGAP 21) (Gly1121Ser), 5) Myosin 1H (MYO1H) (rs10850110).

Face Mask Therapy and Comprehensive Orthodontic Treatment for Skeletal Class III Malocclusion: A Case Report.

Aim: This article aims to report a case of face mask therapy and comprehensive orthodontic treatment for skeletal class III malocclusion in a 16-year-old girl. Background: Treating skeletal class III malocclusion in a growing patient is crucial, as it can help avoid the need for additional surgery. Early treatment also lessens the negative impacts of the patient's facial abnormality on their social life because surgery is only done later. Case description: In this case report, a 14-year-old female patient presented with skeletal class III malocclusion with primary complaints of anterior crossbite. There was no relevant medical history. Face mask therapy and fixed appliance therapy were components of the treatment approach that successfully corrected the malocclusion. The total period of treatment was 20 months. Conclusion: The treatment resulted in a harmonious face, a well-aligned smile arch, stable dental and skeletal relationships, and significant esthetic improvements, including improved facial symmetry and profile. Significance: A growing teen who has a skeletal class III malocclusion and a maxillary deficit may be helped by a combination of face mask therapy and thorough orthodontic treatment. This case report outlines the use of the aforementioned technique to successfully treat a 14-year-old child with class III malocclusion and maxillary deficiencies.Early management of skeletal class III malocclusion in developing adolescents is vital as it can potentially eliminate the necessity for future surgical intervention, leading to improved treatment outcomes.Careful case selection, patient cooperation, and long-term stability enable a successful, stable, and esthetically pleasing treatment outcome. How to cite this article: Le LN, Do TT, P Le KV. Face Mask Therapy and Comprehensive Orthodontic Treatment for Skeletal Class III Malocclusion: A Case Report. Int J Clin Pediatr Dent 2024;17(3):368-376.

The use of miniplates for nontraditional orthodontic treatment: clinical considerations for referring general dentists.

Distalization of mandibular molars comes with significant challenges, especially in adult and young adult patients. In selected cases, third molar extraction procedures offer the opportunity to place miniplates for anchorage to distalize mandibular molars, providing additional solutions to the traditional extraction of premolars or a single incisor. This approach can be of special interest to adult patients, who may have life commitments and time restraints that limit traditional orthodontic and surgical treatment options, and it can improve the efficiency of dental care. This case series describes 3 clinical scenarios in which miniplates were placed with minimal invasiveness during the removal of impacted third molars, offering the patients nontraditional orthodontic treatment options. Awareness of these options is essential for general dentists so that they can explain all treatment possibilities and provide appropriate referrals to patients with impacted third molars.

A preliminary investigation into the impact of soft tissue augmentation-based periodontal phenotype modification therapy for patients exhibiting class III decompensation.

BACKGROUND: Patients with skeletal angle Class III malocclusion usually have inadequate hard and soft tissue volume at the mandibular anterior teeth. The labial proclination at the teeth may lead to gingival recession. The purpose of this study was to explore whether periodontal phenotype modification therapy with soft tissue augmentation (PhMT-s) can prevent gingival recession in these patients. METHODS: Four patients with skeletal Class III malocclusion and a thin periodontal phenotype underwent surgical-orthodontic treatment. Prior to tooth movement, they underwent a minimally invasive vestibular incision with subperiosteal tunnel access combined with autogenous connective tissue grafts for periodontal phenotype modification with soft tissue augmentation (PhMT-s). The labial gingival thickness of the anterior mandibular teeth was measured at three distinct levels: at the cementoenamel junction (GT0), 3 mm apical to the CEJ (GT3), and 6 mm apical to the CEJ (GT6). These measurements were taken at baseline, three months following PhMT-s, and after tooth decompensation. Additionally, a biopsy sample was obtained from the PhMT-s site of one patient. All sections were subsequently stained using hematoxylin and eosin, Masson trichrome, Sirius Red, and immunohistochemistry. RESULTS: The thickness of the labial gingiva was increased about 0.42 to 2.00 mm after PhMT-s. At the end of pre-orthognathic surgical orthodontic treatment, the thickness of the labial gingiva was increased about - 0.14 to 1.32 mm compared to the baseline and no gingival recession occurred after the pre-orthognathic surgical orthodontic treatment. The histologic results demonstrated that the grafts obtained from the PhMT-s site exhibited increased deposition of collagen fibers. Moreover, the proportion of type III collagen increased and the grafts displayed significantly reduced positive expression of CD31 and OCN. CONCLUSIONS: PhMT-s increased the thickness of the soft tissue, stabilizing the gingival margin for teeth exhibiting a thin periodontal phenotype and undergoing labial movement. This is attributed to the increased deposition of collagen fibers.

Achieving Aesthetics and Function in Class III Malocclusion Through Orthodontic Camouflage: A Clinical Case Report.

Class III malocclusion is a challenging dental and skeletal condition characterized by a protrusive mandible, retrusive maxilla, or a combination of both. Treatment options include growth modification, orthodontic camouflage, and orthognathic surgery. While surgery often provides definitive results for severe cases, orthodontic camouflage is a viable alternative for managing mild to moderate skeletal discrepancies in adults. This case report illustrates the successful use of orthodontic camouflage in a 19-year-old female with skeletal and dental class III malocclusion, emphasizing nonsurgical strategies to achieve functional and aesthetic improvements. The patient presented with concerns about her bite and facial profile. Clinical examination revealed a concave profile, prominent mandible, and class III molar and canine relationships with a negative overjet. The radiographic analysis confirmed a skeletal class III relationship (ANB angle of -2°) and normal vertical growth patterns. The chosen nonsurgical treatment plan involved fixed orthodontic appliances and class III intermaxillary elastics to correct the malocclusion and improve facial aesthetics. The treatment phases included initial alignment, class III elastic application to adjust the occlusion, and detailed finishing to refine results. After 20 months, the treatment resulted in a positive overjet, class I molar and canine relationships, and improved facial aesthetics with reduced mandibular prominence. The patient expressed satisfaction with both functional and aesthetic outcomes. This case demonstrates that orthodontic camouflage can effectively manage mild to moderate class III malocclusion in non-growing patients. Successful outcomes depend on precise treatment planning, patient compliance, and regular monitoring. While surgical options remain necessary for severe cases, orthodontic camouflage provides a less invasive alternative for suitable patients, significantly improving dental function and facial aesthetics.

Stepwise surgical management of binder syndrome with skeletal class III malocclusion in adults.

Our study aimed to evaluate a stepwise treatment of class III malocclusion accompanied with flat nasal deformity, using orthodontics, orthognathic surgery, and rhinoplasty, as well as stability during long-term follow-up. In total, 27 patients with nasomaxillary hypoplasia and skeletal class III malocclusion were enrolled in this study. All patients had accepted orthodontic and orthognathic surgery, followed by rhinoplasty with costal cartilage as the second surgical procedure. Clinical results were evaluated by radiography, medical photography, questionnaire, and cephalometric analysis. All patients were satisfied with the surgical results and no serious complications occurred. During the follow-up, the patients showed well-corrected midface contour and nasal projection, and stable occlusion. The costal cartilage grafts were well fixed, without obvious absorption deformation. Lateral cephalometric analysis and overlay results showed that the postoperative point A had advanced approximately 5.20 ± 1.43 mm and the SNA angle had increased by approximately 5.59 ± 2.86°. Soft-tissue measurements showed a 14.22 ± 6.56° decrease in the facial lobe, while the nasolabial angle had increased by 16.83 ± 6.65° postoperatively. The results suggested that stepwise orthodontic-orthognathic surgery and rhinoplasty produce a predictable and stable result in long-term follow-up.

Class III correction and enhanced periodontal health with aligner treatment in a 53-year-old patient.

In this case report, we describe the successful camouflage treatment of a 53-year-old female with dental and skeletal Class III malocclusion combined with anterior crossbite, gingival recession, and mobility of the lower incisors, using clear aligners. The treatment involved periodontal debridement followed by orthodontic treatment. The mandibular posterior teeth were distalized to correct the anterior crossbite and to establish Class I molar relationships. During treatment, the mandibular incisors were intruded, and the mandibular occlusal plane underwent a clockwise rotation due to slight extrusion of the maxillary buccal segments and distalization of the mandibular posterior teeth. Following treatment, all objectives were achieved, including resolution of the anterior crossbite, significant reduction of gingival recession and tooth mobility, and improved functional occlusion. The dental and skeletal Class III malocclusion was corrected, and the marginal alveolar bone dehiscence was significantly reduced. The results remained stable over a 3-year retention period, with enhanced molar intercuspation and gingival growth progression. This case adds to the evidence supporting the adaptability and effectiveness of clear aligners in treating orthodontic patients with compromised periodontium. The treatment outcomes support that orthodontic treatment using clear aligners, combined with periodontal monitoring, can assist in managing alveolar bone defects, gingival recession, and tooth mobility.

Class III Camouflage Orthodontic Treatment in Adult Patient with Anterior Crossbite and Abnormal Functional Shift: A Case Report.

Skeletal Class III malocclusion is a complex malformation with a prevalence of 81.6% in Airlangga University Dental Hospital, distributed in patients aged 15-45 years old. Camouflage treatment of skeletal Class III malocclusion improves prognosis with a mild-to-moderate shift. This study aimed to discuss orthodontic camouflage as an option for adult patients with Class III malocclusion, emphasizing its indications, implications, and expected results. This report presents the case of a 17-year-old male patient with poor facial aesthetics associated with protruded chin, abnormal functional shift, and temporomandibular joint pain. The facial profile was concave with lower anterior multiple diastemas, mandibular lip protrusion, mandibular displacement, and anterior crossbite. This case was treated by camouflage therapy using straight wire appliance system combined with elastic class III. After 24 months of treatment during the pandemic, the mandibular displacement and the crossbite were corrected, the teeth were arched, the anterior crossbite fixed, and the profile became convex. Camouflage orthodontic treatment can be an effective management option to achieve functional occlusion, stability, and a satisfactory aesthetic impression in adult patients with mild to moderate skeletal Class III deformities, anterior cross bite, and functional shift.

Ectopic eruption of maxillary first permanent molars: Risk factors and association with alveolar and maxillary characteristics on children.

Background/purpose: The etiology of the ectopic eruption (EE) of the maxillary first permanent molars (FPM) remains unclear and controversial. This study was designed to explore the dental and skeletal factors for EE of the FPM in children. Materials and methods: Children aged 6-10 years were recruited to this study. Subjects were assigned to the ectopic eruption group (EEG) and the normal eruption group (NEG). Lateral cephalometric radiographs and panoramic radiographs were measured by angular and linear indices. Results: The prevalence of EE of maxillary FPM was higher in males and at younger ages. Subjects with skeletal class III malocclusion were more likely to be diagnosed with EE of maxillary FPM. The SNA, ANB, FMIA, Wits, Ptm-A, ANS-PNS, overbite, and overjet were significantly different between the EEG and the NEG. The length of the posterior region of the maxillary alveolar bone, U6-OP, and eruptive angulation of the maxillary FPM were statistically different between the two groups. Conclusion: Male sex, skeletal class III malocclusion, mesial inclination of the maxillary FPM, hypoplasia of the maxilla, and insufficient length of the posterior region of the maxillary alveolar bone were related to EE of the maxillary FPM.

Differential outcomes of jaw bone position after surgical-orthodontic treatment in three types of skeletal Class III asymmetry patients.

BACKGROUND/PURPOSE: Facial asymmetry is common in Class III patients requiring orthognathic surgery. This study aimed to analyze jaw bone position after surgical-orthodontic treatment in three types of skeletal Class III asymmetry patients. METHODS: The retrospective study included 30 Class III patients who underwent surgical-orthodontic treatment comprising LeFort I osteotomy and bilateral sagittal split osteotomy (BSSO) without genioplasty. Cone-beam computed tomography (CBCT) images obtained before surgery (T1) and after post-surgical orthodontic treatment (T2) were superimposed with voxel-based registration. Patients were classified into three groups based on T1 CBCT scans. Groups 1 and 2 exhibited menton and ramus deviated to the same side. Menton deviation was larger than ramus width asymmetry in group 1, while the reverse was true for group 2. Group 3 had menton deviation contralateral to the side with greater ramus width. RESULTS: Menton deviation after treatment was improved in all groups. Ramus width asymmetry and coronal ramus angle difference decreased in groups 1 and 2. Neither improvement nor deterioration of ramus width asymmetry was noted for group 3. Comparing to groups 1 and 2, group 3 had greater roll and yaw rotations of distal segment, more upward pitch of proximal segment on chin deviation side, and largest inward yaw as well as backward translation of proximal segment on non-deviation side. CONCLUSION: The positional changes of osteotomy segments differed among three types of mandibular asymmetry. Special attention should be given to the atypical mandibular asymmetry with mandibular body and ramus deviating to opposite directions during surgical correction of jaw deflection.

Clinical Management of Facemasks for Early Treatment of Class III Malocclusion: A Survey among SIDO Members.

To evaluate whether there are differences among orthodontists in the clinical management of facemask treatment for early treatment of Class III malocclusion, a survey consisting of 16 questions was conducted among members of the Italian Society of Orthodontics (SIDO). Sixty percent of the respondents were Specialists in Orthodontics (S) whereas 40% were General Dentists practicing Orthodontics (GD). Descriptive statistics were calculated to summarize the collected data. Differences in answers between S and GD were assessed with the Fisher's exact test for dichotomous variables, chi-square test for qualitative variables, and Mann-Whitney test for ordinal variables. A total of 151 clinicians participated in this survey. As for treatment timing, about 80% of the participants reported treating Class III patients with RPE and facemask between 5 and 8 years of age. Most of the participants requested the patients to wear the facemask in the afternoon and at night for a period of 9 or 12 months with recommended forces of 500 g per side. Comparisons between S and GD showed that S preferred the Petit facemask whereas GD favored the Delaire's type facemask (Fisher's Exact test, p = 0.0005). S and GD also differed significantly in their judgment of the most critical time of treatment, which for the majority of GD was the initial period but for the S was the final period (Chi-square test p = 0.0188). This survey showed that the facemask is not well received by the patients who, along with their parents, express concerns regarding its tolerability.

Machine Learning Algorithms for the Diagnosis of Class III Malocclusions in Children.

Artificial intelligence has been applied to medical diagnosis and decision-making but it has not been used for classification of Class III malocclusions in children. OBJECTIVE: This study aims to propose an innovative machine learning (ML)-based diagnostic model for automatically classifies dental, skeletal and functional Class III malocclusions. METHODS: The collected data related to 46 cephalometric feature measurements from 4-14-year-old children (n = 666). The data set was divided into a training set and a test set in a 7:3 ratio. Initially, we employed the Recursive Feature Elimination (RFE) algorithm to filter the 46 input parameters, selecting 14 significant features. Subsequently, we constructed 10 ML models and trained these models using the 14 significant features from the training set through ten-fold cross-validation, and evaluated the models' average accuracy in test set. Finally, we conducted an interpretability analysis of the optimal model using the ML model interpretability tool SHapley Additive exPlanations (SHAP). RESULTS: The top five models ranked by their area under the curve (AUC) values were: GPR (0.879), RBF SVM (0.876), QDA (0.876), Linear SVM (0.875) and L2 logistic (0.869). The DeLong test showed no statistical difference between GPR and the other models (p > 0.05). Therefore GPR was selected as the optimal model. The SHAP feature importance plot revealed that he top five features were SN-GoMe (the ratio of the length of the anterior skull base SN to that of the mandibular base GoMe), U1-NA (maxillary incisor angulation to NA plane), Overjet (the distance between two lines perpendicular to the functional occlusal plane from U1 and L), ANB (the difference between angles SNA and SNB), and AB-NPo (the angle between the AB and N-Pog line). CONCLUSIONS: Our findings suggest that ML models based on cephalometric data could effectively assist dentists to classify dental, functional and skeletal Class III malocclusions in children. In addition, features such as SN_GoMe, U1_NA and Overjet can as important indicators for predicting the severity of Class III malocclusions.

A nomogram prediction of gingival recession in mandibular incisors of orthodontic-orthognathic treated skeletal class III malocclusion with or without PAOO: A retrospective cohort study.

Background: To assess the alterations in gingival thickness and the occurrence gingival recession subsequent to orthodontic-orthognathic treatment of mandibular incisors in skeletal Class III and identify risk factors associated with gingival recession. Methods: In this retrospective cohort study, we enrolled 33 patients exhibiting skeletal Class III malocclusion, totaling 131 mandibular incisors, who were undergoing orthodontic- orthognathic treatment that did not involve extraction of mandibular teeth. The subjects were categorized into surgery group (S; n = 17; ANB = -5.55 ± 3.26; IOFTN = 4.60 ± 0.51, scores ranging: 4.3-5.3) and non-surgery group (NS; n = 16; ANB = -3.00 ± 4.08; IOFTN = 4.63 ± 0.50, scores ranging: 4.3-5.4), based on if they had history of Periodontally Accelerated Osteogenic Orthodontics surgery (S) or not (NS). Patients in S group received orthognathic surgery about 1-1.5 years after Periodontally Accelerated Osteogenic Orthodontics surgery. Alterations in gingival thickness, gingival recession, and keratinized gingival width were compared before and after orthodontic-orthognathic treatment. Logistic regression analysis was used to construct a gingival recession prediction model and draw nomograms. Results: After orthodontic-orthognathic treatment, the gingival thickness and keratinized gingival width in NS group decreased by 0.15 ± 0.21 mm and 0.74 ± 0.91 mm, whereas those in the S group increased by 0.32 ± 0.28 mm and 2.09 ± 1.51 mm (P < 0.05). After orthodontic-orthognathic, the percentage of gingival recession increased by 47.62 % in NS group, which was 14.77 times that of S group (P < 0.05). Multivariate regression analysis indicated that skeletal Class III patients with a gingival thickness below 0.72 mm, an alveolar bone height exceeding 2.36 mm, and an alveolar bone thickness under 0.45 mm might be at elevated risk for developing gingival recession following orthodontic - orthognathic therapy. Conclusions: Drawing on the findings of our investigation, we concluded the risk of gingival recession of mandibular anterior teeth increased after orthodontic-orthognathic treatment in skeletal Class III, whereas Periodontally Accelerated Osteogenic Orthodontics surgery could significantly improve the periodontal phenotype and prevent gingival recession.

Mapping the evolving trend of research on Class III malocclusion: a bibliometric analysis.

OBJECTIVES: This study aimed to provide visualized knowledge maps to show the evolving trends and key focal points of Class III malocclusion research through a comprehensive bibliometric analysis. MATERIALS AND METHODS: Class III malocclusion research published between 2000 and 2023 was retrieved from the Web of Science Core Collection. VOSviewer was utilized to count the citation and publication number of authors, institutions, countries and journals. Co-occurrence, co-citation, and cluster analyses and burst detection were conducted using CiteSpace. RESULTS: A total of 3,682 publications on Class III malocclusion were included in the bibliometric analysis. During 2000-2023, both the annual publication count and citation frequency exhibited a gradual upward trajectory, with a noticeable surge in recent years. In terms of production and citation counts of Class III malocclusion research, the core journal is the American Journal of Orthodontics and Dentofacial Orthopedics. Furthermore, apart from the primary keyword 'Class III malocclusion', 'orthognathic surgery' was identified as keyword with the most frequency. The cluster analysis of cited references reveals that the research focal points have shifted to 'skeletal anchorage' and 'surgery-first approach'. Furthermore, the burst detection identified 'quality of life' as a potential research hotspot since it has recently gained increasing scholarly attention. CONCLUSIONS: The current study provides scholars with the knowledge maps of evolving trends and prominent topics of Class III malocclusion research and a summary of research progress on various priorities during different periods. These findings are expected to provide a valuable guidance to facilitate the future research on Class III malocclusion.